Repeater for signaling circuits



Patented Dec. 8, 1931 I' @UNITED STATES 4lxfralwr oFFlcE MOBGENSTEBN, FKETUG'HEN, NEW JERSEY, ASSIGNOR T0 TEE WESTERN 'UN'ION TELEGRAPHCOMIPANYfOF NEW YORK; N. Y., A CORPORATION'- OF NEW YORK waarna rois|sIeNALrie crncurrs Application lled February 7, 1980. Serial No.426,676.

tion of a plurality of field windings of a gen-v erator in accordancewith signals transmitted 15 over the signal transmission system.

Another object of this invention isto provide a thermionic vacuum tube,havmg cirl cuits thereof associated with lines of a slgna'l transmissionsystem, for unbalancing elec-rm '20 trically balanced field windings ofa generator lin accordance with signals transmittedover the signalltransmission system.

Still another object of their invention is to provide circuits forcontrolling the-field excitation of a generator repeater in accordancewith signaling energ by une ually energizing selected field win ings oft e generator.

A further object is tov lrovide a plurality of thermionic vacuum .tu sfor controlling the magnitude and duration ofthe field excitation of ageneratorin accordance with signaling energy impressed upon circuits -ofthe thermionic vacuum tubes.

Other features and objects of this invention will be apparent tothose'skilled in the art to which th1s inuenton pertains from thefollowing specification and the appended claims:

In accordance with this invention signaling energy is impressed upon theinput circuit of a thermionc vacuum tube, the out ut circuit of whichhas a plurality of fiel windings of a generator associated therewithwhereby the cenditionsof excitation of the ieldvof the generator arecontrolled infaccordance with the signalin energy impressed. upon theinput circuit of t e tube. In modified forms of. this invention aplurality of thermionic vacuum tubes are arranged to control theexciting current supplied to the field windings of generator inaccordance with in coming signals. f

This invention will be more fully underlstood from the following seciiication and the drawings, in which brieii) Figure l illustrates anembodiment of this invention, employing a sinvle three elementthermionic vacuum tube fnor controlling a generator having three el'dwindings.

'Figure 2 illustrates a modified form of this Ainvention in which aplurality of thermionic vacuum tubes are employed in independent field'windings of a generator.`

t, Figure 3 illustrates a further modification of this invention inwhich a plurality of therthe polarity and duration of energization of aplurality of ield'windings of a generator; an

. VFigure (l illustrates a further embodiment (if this invention which'is similar'to that illustrate'dl in Figure' 3.`

Referring in detail, to Figure 1 of thev drawings reference numeral 1'desi nates a variable resistance connected in serles with a variableinductance 2 betweenthe control or grid electrode and the cathode of thethermionic vacuum tube 3. Incoming signal transmission lines A and B areconnected across the resistance .1 and inductance 2 to the gridelect-rode and cathode of the vacuum tube 3 for impressing signalingenergy upon the circuits thereof., Source Llisprovided for supplyingheating current to the cathode of Athe vacuum tube 3J Source 5 which isprovided to supply the anode current` to the Vacuum tube 3 is connectedthrough the winding 9 of the differential meter 7 and the winding 11 ofthe field circuit of the generator vmionic vacuum tubes are employed tocontrol v 15'to the cathode. The winding 8 of the meter 7 is connectedacross the source 5 through another. eld winding 10 of the generator 15and the variable resistance 6. Field 5 winding 12 is connected in serieswith the variable condenser 13 across the lield wind-` ing 11. Thewindings and 11 are arranged in circuit so that the. magnetic fluxes setup by currents flowing throu h them from the source 5 will be inopposition.y {Ihe armaturel 14 is connected to the voutgoing lines C andD. f In operation the variable resistance 6 of the embodiment of thisinvention illustrated in Figure 1 is adjusted until the`deiecti'on ofthe differential meter 7 iszero when no signaling energy is-A beingimpressed upon the. input circuit of the vacuum tube 3. The currentsflowing through the windings 10 and 11 of the iield lof the generator 15are ,then equal, and the magnetic luxes of these wind'- ings justneutralize 'each other so that no potential exists across the armatureterminals of the generator 15. When signals are transmitted to the inputcircuit of the repeater over lines A and B an increase or decrease inthe current flowing through the field winding 11 will be eected. If thesignals iinf pressed upon the input of the repeater are of such polarityas to cause the grid electrode of the thermionic vacuum tube 3 to be ata' positive potential with respect to the cathode, 'then theanodecurrent through-the tube will increasel and the magnetic flux set up bythe winding 11 will also increase. The potential across the armature 14of the generator will then cause a signal to be transmit-ted overthelines C Vin a certain direction. When the signal impressed upon theinput of the thermionic tube 3 is of such a polarity as to cause 'thegrid electrode to become negative with respect tothe cathode, the anodecurrent isthen caused to decrease, in accordance with thesignal, and theexcitation of the held/winding 11 consequently also decreases.Themagnetic lield of .the winding 10 will then predominate over that ofthe winding 11. Since the ma etic fields of the windings 10 and 11 are1n opposition to 56 each other the field of winding l() will cause f apotential to exist'across the armature 14 of enerator 15 in a senseoppositeto that caused y the field v of winding 11. The signalstransmitted over the lines C and D will be in acertainY direction whenthe grid potential of the thermionic vacuum tube 3 is caused to increasewith respect tothe-potential of the filament by the mcoming si theopposite .direction when t e potential of the grid electrode of tube 3''is' caused to decrease with respect to that of the cathode by theincoming signals. It is, of course,l apparent that the proper gridelectrode biasing potential may be provided between the-grid c5electrode and the cathode of tube 3 in order vsist'ance 1 and inductance2 of the shunt circuit across the input of the thermionic vac-` als andin @tube 19 is connected between the cathode and nseaooc to operate thistube over any desired portion of its grid voltage-anode currentcharacteristic curve. Line distortion-of incomlng s1gnals can lbecorrected by adjusting the reuum tube 3, to give this shuntcircuit theproper impedance and phase angle in relation to the line circuit.'`

Where it is desired to compensate for the. attenuation caused by thetransmission lines particularly on signals of the higher frequencies an.additional field winding 12 which is connected across the winding 11through the condenser 13 is provided. By proper adjustment of thecondenser 13 with respect to the inductance of the winding 12 thecurrent through the field winding 12 can be made to .increase as the freuency increases. As a result of this the potentlal across the ar- :SFImature 14 will increase as the frequency increases. Since the effect ofa line is to attenuate the higher frequency signals to a l greaterextent than the low frequency signals, the Iinal result of increasingthe aplied potential at the transmitting end of the ine as the frequencyof the signal increases is that the relationship of the signals arrivinat the receiving end of the line will be su stantially as originallytransmitted, that is, they will be equally attenuated in s far asfrequency attenuation is concerned.

In Figure 2 of the drawings 'an embodiment of this invention wherein twothermionlc vacuum tubes are employed 1s illusico trated.` Variableresistance lf3-and variable inductance 17 are connected between theincoming lines E and F and between the grid electrode and cathode ofthermionic vacuum tubes 18 and 19. The connections to the 105 tubes 18and 19 are reversed in that the line .E is connected to the gridelectrode oftube 18 and the cathode of tube 19 while the line l F isconnected to the cathode of tube 18 and the grid electrode of tube 19.Sources 20 and 110 21 are provided 'for heating the cathodes of thetubes 18 and 19, respectively, to the proper temperature. It is, ofcourse, understood that a single source of heating current may beemployed in pla/ce of sources 20 and 21 115 I ode and anode of the tube18 through the 'in-:J

iield winding 23. An additional iield wind-r lng 24 is connected inshuntwith the Winding 23 through the variable condenser 24.

A source of anode current supply 26 for anode thereof through the fieldwinding 27. The magnetic fields set up by the windings 23 and 27 are inopposition to each other. A, field winding 28 is connected in shunt tothe winding 27 through a variable condenser 29. 130 4 vpressed upon theinput circuits of the tubes 18 and 19 the anode currents lin vthe anodecircuits of these tubes will set up magnetlc fluxes in the windings 23and 27 which will vneutralize the effects of one another upon thearmature 30. When a signal is impressed upon the input circuits of tubes18 and 19 in such a manner that the grid electrode of tube 18 ispositive and `the grid electrode of tube 19 is negative with respect tothe cathodes of tubes -18 and 19, respectively, the anode currentthrough the field winding 23 will 1ncrease and that through the fieldwinding 27l will decrease. The effect of the magnetic field of winding23 will then predominate and a potential of positive I polarity will beimpressed across the lines and I. If the signals impressed upon theinput circuits of tubes 18 and 19 are such as to cause the gridelectrode of tube 19 to be at a positive potential with respect to thecathode thereof the anode current through the field winding 27 willincrease and the magnetic field set up by this winding will predominateoverthe magnetic field set up in the winding 23, since the currentthrough this latter winding will de'- crease, and a potential ofnegative polarity is caused to exist between the lines H and I.

In the embodiment of this invention illus# trated in Figure 3 of thedrawings, a transf former comprisingv the variable inductance prlmarywindlng 31, which is connected to the incoming lines through thevariable resistance 32. and the secondary 33, which is variably coupledto the primary 31, is employed to couple the incoming lines to the Inputcircuits of thermionic vacuum tubes 34 and 35. The center of thesecondary 33 is connectedto ground. The cathodes of tubes 34 and 35 arealso connected to ground. The ends of the secondary 33 are connected tothe grid electrodes of tubes 34 and 35. The source 36 of anode currentsupply is connected to the anode of tube 34 through the field winding 37and to the anode of tube 35 through the field winding 38. Field winding39 is connected in shunt With winding 37 through the condenser 40, andanother field winding 41 is connected in series with the condenser 42across the winding 38. A shunt field core 43 is connected across thearmature 44 and theoutgoing lines.

In the arrangement illustrated in Figure 3 the grid electrodes of thethermionic vacuum tubes 34 and 35 are energized by signaling erergylfrom the incomingsline only as long asy the current through the primary31 isffl changing. As soon as the` stead" state i'sH reached in thecurrent flowthroug the prif mary 31 no potential due to signaling energy70p4 will be applied to the grid 'electrodes of tubes 34 and 35,although'a direct current potential exists across the primary.v In orderthat signal current may stillbe'transmitted over the outgoing line aslong as the steady potenv"U5 tial exists on the incoming'line eventhough no grid otential is applied to the grid elec trodes o the tubesthrough the action 'of signaling energy, the shunt winding 43 isprovided across the armature 44. The field set 490 up by this shuntwinding by a current frenera'ted in the armature 44 when thek eldwindings associated with the output circuits of the thermionic vacuumtubes 34 and 35 are energized,'through the actionof the initial 85impulse of a signal, is sustained, since shunt generators areself-exciting. The steady portion of signals transmitted over theincoming lines is thus reproduced on the4 outgoing lines in the properpolarity. Windings 37 and 41 are provided to com, pensate for frequencyattenuation of the outgoing line in the manner described in c on-Ajunction with the description of Fig. 1.

Another arrangement in which a A single thermionic vacuum tube 48` iscoupled to the incoming line thereof, thetransformer 46, the primary ofwhich is connected to the incoming lines through the 'resistance 45, fortransmittin signaling impulses to the field 100 windings oy a generatorassociated with the outgoing line is illustrated in .Figure 4 of thedrawings. This arrangement also em'- ploys a shunt field 57 whlch isconnected -across the armature 58, for exciting the gen'- 105 eratorwhile the steady portion of the signal is being transmitted from theincoming line to the outgoing line. x

The current flowing through the field winding 54 and the winding 52 ofthe differ- 110 ential vmeter 50 from the source 49 is adjusted i to beof the same magnitude as the current flowing through lthe anode circuitof the thermionic vacuum tube 48', the field winding 53, and thewinding-51 of the differential 115- meter 50 from the source 49. Whensignaling energy is impressedupon the incoming line and is increasing invalue, a potentialV proportional to the rate of change of this signalingenergy is impressed between thel grid electrode and the cathode oftheth'ermionic vacuum tube 48. This causes the current through the fieldWinding 53 to either increase or to decrease, de ending uponl Whetherthe grid electrode 1s positive .or 125 negative with respect to thecathode. If the lcurrent through the field'53 increases,.then

the magnetic field set up by it will predominate over the field set upby the current through the winding 54, and a positive im.-

pulse will besenturom the armature 58 o'ver the outgoing line. A currentwill also flow through the shunt winding 57, whichy will maintain` theexcitation of the generator so that the .positive signal will continueto be transmitted over the line as long as it is being" transmittedoverv the incoming line. When the incoming signal ceases, the magneticflux fthrough the windings ofv transformer 46001- lapses, andmomentarily generates a nega-y -tive potential which` is impressed uponthe i grid of the-tube 48. The current throu h 1 the field winding 53 isthereby caused to ecrease by an amount equal to the increase at thebeginnin of the si al impulse, thus causing .the fiel of winding 54 tomomen-- tarily predominate and overcome the eiect of the shunt eld 57.Thus the current imd pulse in the outgoing lline ceaseswith the the endof the outgoing line at the saine .given It is,1:of course, understoodthat while I have described-several embodiments of my invention indetail, variations may be made `therein without departing from the sco eof my claims. Any ofcthe arrangements s own in Figures 1, 2, 3 and 4 canbe. applied to a duplexed telegraph circuitby placing the input circuit'of the Vacuum tubes and apparatus associated with them across theproper points of-a correctly' designed bridge and carrying the armatureconnections o f'tlie generator to the ro er points on the outgoing bride in the up ex circuit on the -line wires to w ich; it is desired torepeat signals.

I claim: ,i

1. Ina signaling systemthe combination of a therinionic vacuum tubehaving input and output currents, a generator lhaving a plurality offield'windings, one of-said field windings bein'g associated with theoutput ,circuit of said thermionic vacuum tube, and

another'of said field windings being connected in shunt with .the`armature' of saidv generator.

2. In a signaling system the combination of a thcrmionic vacuum tubehaving input and output circuits, a generator having a plurality offield windings, selected ones ofA said field windingsbeing associatedwith the output circuit of said .'thermionic va'cuuin tube, said Held.windings being arranged to normally neutralize .the excitation e'ect onsaid generator, said therinionic vacuum tube being. arranged to disturbthe neutralized effect of said field windings when a signal is impresseduponthe input circuit thereof.

3. In a signaling system the combination of a thermionic vacuum tube,` avariable im pedance associated with the input circuit of said tube, agenerator, a plurality of field of a thermionic vacuum tube, a generatorhaving a plurality of `field windings, selected ones of said fieldwindings being associated with the output circuit of said vacuum tube,

one of said field windings being shunted 'across the armature of'saidgenerator, and.

variable reactance` means being associated with one of said fieldwindings.

5. In a signaling system the combination of a plurality of tliermionicvacuum tubes, means for impressing signaling energy upon 4. In asignaling system the combination' the input circuits of said vacuumtubes, a

generator having a fplurality of field windings, selected ones o saidfield windings being'arranged to set up) magnetic fieldsin 0pposition,connections etween the out ut circuits of said thermionic Vacuum tu esand said field windings whereby the potential across the armature ofsaid generator is controlled by the signaling energy impressed upon saidinput circuits, andmeans associated with one of said field windings forincreasing theexcitation of said generator with increase in signalfrequency.

6. In a signaling system the combination of a plurality of thermionicvacuumv tubes, means for impressing signaling energy upon the inputcircuits of said vacuum tubes, a generator having a plurality offieldwindings, selected ones of said field windings being associatedwiththe output circuits of said thermionic vacuum tubes, at least oneof saidfield windings bein connected in shunt with said armature, sai shuntwindin being ar-` ranged to excite said generator uring the duration ofa steady signal impulse.

7. Ina signaling system thecombination Ito prevent excitation 'of saidgenerator under normalv conditions','connections between said fieldwindings and circuits of said vacuum tubes -whereby energy is impressedupon the circuits 4of said field windings 'when signaling energy isimpressed upon the circuits of iso.

said tubes7 whereby said balanced condition in said eld windings isdisturbed, and means associated with one of said field windingsv4gization of one of said field windings in accordance with incomingsignalsl and an outgoing line and another of said field windingsconnected across said armature.

In testimony whereof I aiiix my signature.

RONALD V. MORGENSTERN.v

